This invention relates to a machine tool that can machine screws in which dimension and shape differ, even if exclusive screw-cutting tools fitting with the shape of screw thread are not used.
Until now, when cutting screws using lathes, etc., they do this machining using the exclusive lathe tools fitting with the shape of flank portions of a screw""s ridge (rill) to be machined.
However, many kinds of tools are necessary, each of which fits with each inclination of flank portion of ridges to be machined, when such method is adopted. Therefore, the setup of these tools takes time as well, as the number of tools is occupied for the screw-machining and the number of tools used for other machining is limited. There was such inconvenience.
This invention is based on in the superscription circumstance, and its purpose is to offer the machine tool, which can machine screws with flank portions of various inclinations by one tool.
In order to solve the above-mentioned problems, the invention mentioned in claim 1 is a machine tool, which has a tool rest that can attachably and detachably equip a turning tool with an insert on its tip, said tool rest is provided so as to be freely driven to move in the first and second axial direction (X, Z axial direction) orthogonalizing for each other, and said tool rest is also provided so as to freely rotate with the third axis (B axis) as a center orthogonalizing for said first and second axial direction and to be positioned at each angle, and which can do screw-machining on a rotating workpiece by said turning tool, comprising:
input means for inputting machining information in the screw-machining;
cutting pattern computing portion, which computes a cutting pattern, in which said screw-machining is executed so as to rotate said turning tool with said third axis as a center and position it, based on the machining information input by said input means; and
screw-machining executing portion executing said screw-machining on said workpiece based on the cutting pattern computed by said cutting pattern computing portion.
The invention of claim 1 so executes the screw-machining based on the cutting pattern in which the turning tool is rotated with the third axis as a center and positioned. So it is possible to machine screws with flank portions of various inclination by a single tool, without machining flank portions of ridges by the tools, as the convention, fitting with the inclination of the each flank portion.
The invention mentioned in claim 2 is characterized as said cutting pattern computing portion computes said cutting pattern in such a manner that the first flank and the second flank of a ridge are machined by the separate process.
The invention of claim 2 machines the first flank and the second flank of a ridge by the separate process. So it is possible to form the different inclination on the first flank and the second flank easily and to easily machine a screw of complicated shape as a saw blade screw.
The invention mentioned in claim 3 is characterized as said cutting pattern computing portion computes said cutting pattern in such a manner that said turning tool is inverted in machining the first flank and the second flank of said ridge.
The invention of claim 3 makes it possible to machine screws of more various shapes, if the turning tool is inverted when machining the first flank and the second flank of the ridge.
The invention mentioned in claim 4 is characterized as said cutting pattern computing portion computes said cutting pattern in such a manner that finish machining for the first flank and the second flank of a ridge are done by the separate process.
The invention of claim 4 makes the high-precise machining of a ridge, if finishing the first flank and the second flank of a ridge by the separate process.